In all other sites as of sometime ago, I retired from the name of Dragon Moray Eels and so I normally no longer assist on something as an eel question anymore, but we are in here were if one other hobbyist who thinks to be a specialist.
Now you will hear differ I think for one other here at swf said to another that this eel you have grows some 30" but it really grows around 38-39" as a full grown adult and will attack most anything when hungry.
Also just for this eel a lone should have a tank as large as a 150 for it too as a number of some other species is an active swimmer and also you need before it becomes more homely, give it a large hiding spot with LR for before you know it, it will attack the hand which feeds it.
I hope that your a tight lid on this tank. Also do get yourself a strong feeding stick and if you value the fish in this tank, you either get the eel out or the fish, and please don`t wait too long to do that.
You will notice that I not ask you about tank size or the fish you have>
Ask around in what I say on the size of this eel, Im sure that somewhere in the forums if not here, one has seen a full grown adult of this species.